In a print device an image is printed on a print medium. Typically a print, device, such as an inkjet printer, comprises one or more print heads that, are arranged to deposit a printing fluid such as ink upon the print medium. The one or more print heads are typically controlled by a print controller. Such a print controller receives an input image to be printed and generates a number of signals to control the print device. Based on these signals the printing fluid is ejected from the one or more print heads. Many print devices incorporate some form of relative movement between the print medium and the one or more print heads so that printing fluid is deposited onto an appropriate area of the print medium. The print controller thus coordinates the timing of the signals needed to control the print device such that an output image is printed in the right place on a print medium.